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Full text of "The Morphology And Evolution Of The Apes And Man"

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three kinds are present. The external longitudinal layer is a complete covering, but it is thicker along the curvatures than on the intermediate parts of the loay. The circular fibres are thickest; they are found in the body and pylorus, but only a few run from the oesophagus into the fundus. The oblique fibres are restricted to the fundus and part of the body to the left side of a downward prolongation of the long axis of the cesophagus, and they form rings as in Man. Consequently there are only two muscular lavers—an outer one of longitudinal iTrres,
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and an inner one of oblique fibres to the lefr and circular
ones to the right. The subserous and sabinucous coats are thin. The mucous membrane is thin and soft, and it exhibits pits and glandular orifices as in Man. It is not greatly folded.
The arteries of the stomach are derived from the three branches of the coeliac axis, and the vessels are arranged as in Man. The gastric veins enter the portal vein (fig. 46).
The nerves are derived from the two vagi and the coeliac plexus. The left vagus runs along the lesser curvature as far as the pylorus.
Deniker, who made a thorough study of the Gorilla, pointed out that the stomach in the human and Gorilline foetuses lies behind the transverse colon, whereas it lies above it in the adult (44). In the adult animal the stomach is more globular than in Man, and the pyloric antrum is better defined. The mucous membrane has many rugae in the pyloric region, but none in the cardiac part. Pits and glandular orifices are present as in Man.
In the Orang the stomach resembles that of the Chimpanzee rather than that of the Gorilla. It is